Rock Identifier

Rock & Mineral Encyclopedia

Search and identify 1,000+ rocks, minerals, crystals, and gemstones — with properties, formation, colors, hardness, and how to tell them apart.

Velvet Obsidian

A black volcanic glass with a soft, velvety internal sheen caused by aligned microscopic inclusions catching the light.

igneous

Smoky Obsidian

Translucent smoky-gray obsidian that transmits a hazy light, intermediate between clear and fully black volcanic glass.

igneous
Gray Obsidian

Gray Obsidian

Obsidian in gray tones, often semi-translucent, colored by light scattering and minor inclusions within the volcanic glass.

igneous

Stripe Obsidian

Obsidian crossed by parallel flow bands of differing color, formed as layers of lava with slightly different compositions froze into glass.

igneous
Yellow Obsidian

Yellow Obsidian

Yellow to golden volcanic glass; natural examples owe their color to iron, though much bright yellow obsidian on the market is manufactured glass.

igneous

Crimson Obsidian

A deep red glass sold as obsidian; vivid uniform crimson material is usually manufactured glass rather than natural volcanic obsidian.

igneous

Cloudy Obsidian

Obsidian with a hazy, cloud-like translucency caused by uneven distribution of tiny bubbles or incipient crystallites in the glass.

igneous
Devitrified Obsidian

Devitrified Obsidian

Obsidian that has partly crystallized over time, growing pale spherulite clusters within the black glass, as in snowflake obsidian.

igneous

Blue Obsidian

Blue-colored volcanic glass; genuine natural blue obsidian is very rare, while much blue obsidian on the market is manufactured glass.

crystal
Snowflake Obsidian

Snowflake Obsidian

A black volcanic glass speckled with gray-white cristobalite snowflakes, formed as obsidian begins to crystallize.

igneous

Midnight Obsidian

A trade name for deep, solid black obsidian, natural volcanic glass prized for its uniform jet-black color and glassy luster.

igneous
Porphyritic Obsidian

Porphyritic Obsidian

Natural volcanic glass speckled with embedded mineral crystals (phenocrysts) such as feldspar or cristobalite that grew before the lava chilled.

igneous
Red Obsidian

Red Obsidian

Volcanic glass tinted red by fine iron-oxide inclusions, often blended with black to form mahogany-patterned obsidian.

crystal

Tangerine Obsidian

A vivid orange glass sold as obsidian; uniformly bright tangerine material is typically manufactured glass rather than natural volcanic obsidian.

igneous
Purple Obsidian

Purple Obsidian

Purple-colored volcanic glass; genuine natural purple obsidian is rare, with much purple obsidian being manufactured colored glass.

crystal

Pastel Obsidian

Soft pastel-colored glass sold as obsidian; multicolor pastel material is manufactured art glass rather than natural volcanic obsidian.

igneous

Peanut Obsidian

Black volcanic glass studded with oval, peanut-shaped grey-white spherulites of radiating crystals frozen in the glass.

igneous

Aurora Obsidian

A trade name for rainbow-sheen obsidian whose aligned nanoparticles produce shifting aurora-like bands of color.

igneous
Brown Obsidian

Brown Obsidian

Obsidian colored brown by iron oxide inclusions, frequently banded or swirled with black as in mahogany obsidian.

igneous

Leopard Obsidian

Black volcanic glass marked with rounded spots and patches that resemble a leopard's coat, caused by spherulitic crystallization.

igneous
Fire Obsidian

Fire Obsidian

A rare obsidian showing brilliant fiery iridescence caused by thin nanolayers of magnetite crystals diffracting light within the glass.

crystal

Lace Obsidian

Black volcanic glass laced with delicate web-like veins of contrasting color, formed by flow banding and fine crystallization.

igneous

Frosted Obsidian

Natural obsidian with a frosted, matte surface produced by weathering, abrasion, or etching rather than a separate variety of glass.

igneous
Banded Obsidian

Banded Obsidian

Volcanic glass marked by parallel or swirling bands of differing color that record the flow layering of cooling lava.

igneous